QCalendarWidget month-year selection

I want to modify the top part of the QCalendarWidget, particularly , I want to modify the dropdown object that allows for month selection

Attachment 7267

In red is the margin of the dropdown I want to modify. In blue you see how I would like it to actually be.

I've succesfully modified QComboBoxes dropdown lists to have each cell have a ¨higher value on Y axis, but I don't know how to access this particular dropdown.

Example of how I want it to look in height.
http://i.imgur.com/ZenwD.jpg

In resume, I want the QCalendarWidget's dropdown to look like the example above and I don't know how to access it.